The blocking of translation of an mRNA by miRNA occurs because the miRNAــــــــــــــــــــــ .

A)binds to the 3'-UTR of the mRNA and prevents translation
B)targets the mRNA for degradation by Slicer
C)binds to the 5'-UTR to prevent the ribosome from binding
D)folds into alternative stem-loop structure and protects the mRNA from nuclease cleavage